1. Field of the Disclosure
The disclosure relates to a pulse width modulation signal generation circuit and method, and particularly relates to a pulse width modulation signal generation circuit and method using a bidirectional counting mode.
2. Description of Related Art
Pulse width modulation (PWM) has been broadly applied in electronic circuits, such as motor control circuits and power supplies. Counter-based pulse width modulation signal generation devices can be categorized into edge-aligned mode and center-aligned mode. Compared with the asymmetrical edge-aligned mode, currents and voltages output by the center-aligned mode with a symmetrical framework have fewer harmonics. Thus, a pulse-width modulation system using the center-aligned mode may reduce power consumption.
However, under the premise that the clock frequency is fixed, the resolution of the pulse width modulation signal may be limited by the characteristic of symmetry of the center-aligned mode. Besides, if the clock frequency is increased to improve the resolution of pulse width modulation in the center-aligned mode, the overall circuit framework needs to be significantly modified, and the dynamic power consumption may also be higher. Besides, there may also be interference of noises.